<html>
<head>
    <meta charset="UTF-8">
    <title>文件上传</title>
</head>
<body>
    <form action="/upload" method="post" enctype="multipart/form-data">
        <input type="text" name="username">
        <input type="file" name="photo">
        <button type="submit">上传</button>
    </form>

    <button type="button" id="btn-add">添加</button>

    <a href="/download">下载test.txt文件</a>

    <script src="/webjars/jquery/3.5.1/jquery.min.js"></script>
    <script>
        $('#btn-add').click(() => {
            alert('点击了添加')
        })
    </script>
</body>
</html>